The present technique relates to a rotatable antenna apparatus, which may be used for example within a telecommunications system.
A rotatable antenna apparatus may be arranged to consist of a fixed unit that is attached to an external structure, for example an item of street furniture such as a lamp post, and a rotatable unit that is mounted on the fixed unit and includes an antenna assembly via which wireless communication signals are transmitted and received.
The antenna assembly needs to be connected to processing circuitry that is used to perform various signal processing operations on the signals to be transmitted by, or the signals received by, the antenna assembly. There are often a significant number of connections required between the antenna assembly and the associated processing circuitry, for example due to the number of individual antennas that may be provided within the antenna assembly, and it is desirable to reduce the length of those various connections in order to reduce signal loss. Accordingly, it would be desirable to place the processing circuitry within the rotatable unit mounted in close proximity to the antenna assembly, as this would reduce the above mentioned losses, and also gives rise to other improvements such as a reduction in lifetime wear issues that would otherwise be present in the various connections between the antenna assembly and the processing circuitry, and certain calibration difficulties that can arise if the processing circuitry is not mounted for rotation with the antenna assembly.
Whilst it is beneficial to have the processing circuitry within the rotatable unit, this can give rise to a heat dissipation issue. In particular, the rotatable unit will typically be sealed from the outside environment via a radome forming an outer enclosure of the rotatable unit. It is desirable in many instances to make the rotatable antenna apparatus relatively small, and accordingly the space inside the radome enclosure is relatively limited. Hence, there is a concern that the heat generated within the enclosure of the rotatable unit from at least some of the components within the processing circuitry could become problematic, reducing the effective lifetime of some of the components, and potentially causing the system to shut down due to overheating.
Accordingly, it would be desirable to provide an efficient mechanism for dissipating the heat from the rotatable unit.